The Spark

“The emancipation of the working class will only be achieved by the working class itself.” — Karl Marx

From the Bubonic Plague to SARS:
A History of Past Epidemics

May 1, 2003

Text from a multimedia presentation at the 2003 festival of Lutte Ouvrière. This text is even more relevant today, in 2020, with the COVID-19 pandemic circling the globe.

A form of atypical pneumonia called severe acute respiratory syndrome (SARS) is a new “emergent” disease. The fact that such a disease is new worries us and makes us turn back to examine a past when medicine was totally powerless, when people fled from places where the epidemic had struck, protected themselves, kept a distance from contaminated people, and isolated those who become ill. We are afraid.

Epidemics have always sown terror, whether smallpox or the Spanish flu, the plague or cholera. There is a popular French expression “to choose between the plague and cholera,” used when things that are so catastrophic that we can’t decide which is worse. Because of their sudden nature, the rapidity of their spread, and the number of deaths they cause, we have experienced epidemics every time as if they were scourges whose return we can only fear.

Until the nineteenth century, the real cause of epidemics remained incomprehensible to us.

Reasonably, humanity could explain them only as supernatural phenomena: the will of evil demons, the wrath of vengeful gods, or fateful astrological alignments.

Unlike SARS [and COVID-19] and AIDS, the vast majority of epidemics are not new. They are part of the history of humanity since our origins. In fact, the agents responsible for these diseases existed long before humans did.

Bacteria, for example, were the first forms of life on the planet. They are almost four billion years old, while our human species has only some three million years of existence behind it. During the course of evolution, as complex living beings gradually began to appear, bacteria adapted to this new environment. By turns, they colonized plants and insects, then fish, amphibians, and reptiles, and then mammals, of which we are one. Some of them even became specialized in the colonization of one species or another.

Hundreds of millions of bacteria live in our bodies. Some of them have lived within our species for so long that our immune systems tolerate them. They are regular guests of the organism. They are sometimes even indispensable to our bodily functions, such as the colon bacillus in our intestines which aid the process of digestion.

On the other hand, other bacteria enter into our bodies only after they have outmaneuvered our defense mechanisms. These bacteria, known as “pathogens,” are at the origin of infectious diseases.

Bacteria are a type of very simple cell only a few micrometers in length, containing a chromosome which carries their genetic material. They reproduce simply by dividing in half. It is this multiplication which is at the origin of the disease, since it takes place at the expense of our tissue. The bacillus which causes tuberculosis, for example, destroys lung tissue.

Viruses are about one hundredth the size of most bacteria and are simply made up of genetic material wound up inside a protein coat. Strictly speaking, they are not alive, since they are unable to reproduce by themselves. In order to reproduce, they must penetrate cells and take over the cellular machinery necessary for reproduction and use it for their own benefit. They most often end up destroying the cells which they infest, like the AIDS virus, which destroys some of our immune cells, and the SARS virus, which destroys our lung cells.

Other infectious diseases are caused by tiny animals which penetrate our body and reproduce within it. These include, for example, trypanosomes which cause sleeping sickness, Plasmodium species which bring malaria, and the tiny worms called blood flukes which are responsible for schistosomiasis. These parasitic diseases are “endemic” to certain regions of the world, killing hundreds of thousands of people every year, especially in Africa.

Our hunter‑gatherer ancestors inevitably encountered microbes—bacteria, viruses, and parasites—and developed infectious diseases.

When they became growers and farmers, and therefore settled, the microbes that colonized animals were able to pass to humans and adapt to them by transforming themselves a little. The microbes that cause tuberculosis, scarlet fever, measles, and the bubonic plague almost certainly originated among other animals.

At the same time, settlement gave rise to the first villages, and then the first cities. These were the first concentrations of population favorable to the spread of pathogenic agents among a large number of individuals. The development of commercial exchanges then favored their spread over distance. From then on, the conditions were in place for the first epidemics to arise.

Our knowledge about infectious agents is very recent. It begins in the second half of the 19th century with Louis Pasteur’s research. We began to identify different microbes, to demonstrate that each infectious disease is caused by a specific agent. Then we developed vaccines.

We then imagined that we would soon discover every microbe and invent ways to protect ourselves and to destroy them. We believed that humanity would finally be rid of infectious diseases.

But we kept on discovering new ones, such as the bacteria that cause legionnaire’s disease, the viruses that cause AIDS or SARS, and prions, the agents which cause mad cow disease, about which we still know almost nothing.

In fact, microbes are an integral part of life, of our lives. They evolve and transform themselves along with us. We cannot imagine their disappearance, since this would mean that we would be gone too. We must live alongside them while benefitting from our deepened understanding in order to limit their harmful effects.

Bubonic Plague

The deadliest plague epidemic known to the Western world was the one in the mid‑fourteenth century. It started in Central Asia around 1340. At that time, silks and furs from China reached European courts. Caravans brought them as far as Caffa, a Black Sea port in the hands of the Genoese, from which the goods were then brought to Europe by boat. This was the route which the plague followed.

In 1347, it struck Caffa. When the Genoese loaded their galleys with eastern riches, they could not imagine what would come next. In October, by the time the galleys made a stopover in Messina on the island of Sicily, half of the crew had perished, and the survivors were in a piteous state.

All of Sicily became infected. Then Naples, Florence, and the rest of Italy. Genoa refused to allow its own galleys loaded with treasure to enter its port, and so they drew up alongside Marseille in France. All of Provence was infected. By land, the epidemic reached the French countryside and the Atlantic ports, and, from there, England. In 1352, the plague came to Scandinavia, Germany, Poland, and Russia.

Death was everywhere. In the space of only four years, Europe, which had between 50 and 60 million inhabitants, lost between one third and one half of its population.

Those infected died after several days, sometimes even in several hours, when they did not collapse immediately. Few among them recovered.

Fear reigned over everything. Nobody understood the plague. Such a scourge could have resulted only from divine wrath as its cause. And so, processions were organized in which people begged for God’s forgiveness and lashed themselves. And who to blame for this wrath—if not the poor, the lepers, and the Gypsies, who were driven off, and the Jews, 2,000 of whom were slaughtered in Strasbourg alone?

The doctors, with their bloodletting and ointments, were powerless. Fleeing from the plague seemed to offer the only hope of escaping the danger. But those who fled too late ended up unknowingly contributing to the spread of the epidemic.

The epidemic then subsided without anyone really knowing why. But the plague did not disappear from the West. For the next 400 years or so, it regularly recurred in all of the major cities, even though it never again caused the same kind of catastrophe as it did in 1348.

The last great epidemic in France was that of Marseille in 1720. On May 25, a ship entered the port. It was known to have made a stop in Syria, which had been struck with the plague. Since 1348, even though nothing else was known about the disease, it was nevertheless observed that quarantine measures were effective in containing epidemics. The ship was therefore quarantined. But it only remained in quarantine for 10 days, after which it unloaded its goods. These were destined for the trading fair in Beaucaire which was supposed to take place in a few days. The merchants could not stand to lose such a market for their goods. By mid‑September, thousands of corpses were piled up in the city. Within six months, Marseille and the surrounding region had lost 30,000 inhabitants. The last great plague epidemic struck at the end of the 19th century. As a result of expanded international trade and the speed of newly‑invented steamships, it began in Asia and reached Africa, before crossing the Atlantic and entering the Americas. This was a true pandemic.

And then, in 1894, the plague bacillus was isolated. Alexandre Yersin, a doctor at the newly created Pasteur Institute, had been sent to Hong Kong in that year to study the disease. One month after he began working in a straw hut with a microscope, he wrote: “It has not been difficult for me to discover the microbe … a little rod, a little longer than it is wide.” This was a “bacillus,” the Yersin bacillus. Several years later, the role of fleas and rats in the disease’s spread was discovered.

The plague bacillus has lived continuously among small wild rodents in Central Asia who hardly seem to suffer from it. The fleas which bite them and therefore ingest the bacillus do not seem to be afflicted by it either. From bite to bite, they spread the bacillus among these rodents, who form the “reservoir” of the bacillus.

But if an infected flea bites a rat, the rat gets the disease and then spreads it to the rat fleas which bite it. And, since rat fleas also bite humans, the bacillus can eventually reach us in this way. Next, the fleas that bite humans guarantee the spread of the disease between humans.

Giant painful swelling occurs in the area surrounding the bite. These are called “buboes,” which gives the disease the name of “bubonic” plague. Afterwards, some plague‑stricken people develop lung infections, which is called the pneumonic plague.

And so, once fleas are no longer needed to spread the disease, humans become the carriers, and the epidemic takes off. We finally understood the rapid development of the epidemics of the Middle Ages, 550 years later.

Today, there are no more great plague epidemics. Some bacillus “reservoirs” still exist, no longer just in Asia, but also in the Americas, and the fleas also continue to exist.

But we have broken the chain of infection between rodents and humans. Rats aboard ships have been systematically exterminated. In the rich countries, hygiene has kept rats and fleas at a distance from us. In this chain, even humans have been changed, since vaccinations have made them less receptive to the plague bacillus. Furthermore, we have developed effective treatments which mean that the plague is no longer a fatal disease if treated in time.

The plague has not been eradicated. Since 1994, it has even been considered a re‑emergent disease. The chain of infection remains intact in Madagascar, India, and Africa, where the plague persists in a chronic and “endemic” state.


In the 15th century, those whom we call the conquistadores, or Spanish mercenaries, quickly conquered the Aztec and Inca empires with their guns, power, and horses, all unknown to the civilizations which then lived on the American continent. It has been estimated that the Americas had 100 million inhabitants before Christopher Columbus “discovered” them. One century later, 95% of them had disappeared. This was the largest genocide of all time. The colonizers’ extreme violence, massacres, and demands for forced labor received unanticipated support from viruses and bacteria.

In 1518, an epidemic broke out in the Caribbean, decimating the indigenous populations. Then, setting out from Cuba, the army of Hernán Cortés brought the disease to Mexico. The Aztec military leaders were certainly conquered by the superiority of Spanish weapons, but also because of the devastation brought by smallpox to peoples who had developed no immunity. With its high mortality, smallpox added a psychological effect. What could the Aztecs conclude from such a scourge, which laid their own armies low while sparing those of the enemy, but that their gods had abandoned them and that the god of the whites was superior?

The epidemic spread from Mexico to Central America and then the entire Inca empire. Next, it reached Brazil, and, for the rest of the century, epidemics followed one after the next, ravaging the indigenous populations.

Other infectious diseases added their damage to that wrought by smallpox. Measles, mumps, diphtheria, and fever—these infectious diseases which had struck the old continent turned out to be tragic in the “new” one.

Humans had first migrated to the Americas 40,000 years before, when small groups set out from Asia across the Bering Strait. This was during an ice age, when the sea level was much lower and it was possible to cross the strait by foot. These first immigrants had contact with the same microbes as the population on the Eurasian continent which they were leaving. Everything seems to suggest that they no longer encountered these on their new continent. In addition, as the sea levels rose with global warming, the two populations, American and Eurasian, had no contact for the next 40,000 years.

And so, when the Spanish armies arrived, it was not only a military shock, but also a bacteriological shock. The Spanish brought microbes with them which the Amerindian populations had not known for millennia. For them, these were new diseases, or “emergent” as we would say today.

The mortality was so high that there was soon a shortage of workers. The Europeans then went to the African continent in search of black slaves. Believed to be more resistant, the African slaves were in fact accustomed to the same microbes as the colonizers. The African population had never been isolated from the Eurasian population.

Later, smallpox also served as an ally to the French and English in the conquest of North America and in the extermination of Indian tribes. This was partially accidental, since these Indian tribes also descended from the immigrants of 40,000 years ago and therefore had no contact with the virus. But it was also intentional.

Smallpox manifests itself, in part, through an eruption of bumps with scabs that leave scars imprinted on the skin once they fall off, marking people’s faces for life. These are the pox that give the disease its name. These scabs contain many viruses which can live for months in clothes and household objects. This method of spreading, even though it was not fundamentally understood, did not escape the colonizers’ attention. They offered blankets infected with smallpox to the Indians to speed up their elimination. In the hands of the Europeans, smallpox was already a “non-conventional” biological weapon. [The same weapon was used by the U.S. army when it pushed to destroy the last resistance of Indian tribes in the West after the Civil War.]

In the old world, people also suffered from smallpox, but in a chronic and endemic form. Like many infectious diseases, it especially struck young children. Children died at a rate of 10‑15%. Due to its chronic nature, it terrified people less than the plague epidemics. We lived with it. Nevertheless, over the centuries, it caused more deaths than the plague.

At the end of the eighteenth century, in England, a doctor named Edward Jenner observed that milkmaids who got cowpox from cows were spared from human smallpox epidemics. He got the idea of scraping pus from cowpox blisters and inoculating healthy subjects with it in order to protect them from smallpox. Since this proved effective, “vaccination” was born (the name derives from the Latin word for cow).

This technique essentially consists of introducing an infectious disease agent, but in a weakened form, so that the organism produces specific substances to fight the microbe called antibodies. And because the immune system then memorizes the process of making these antibodies, when the organism comes into contact with the same microbe a second time, the antibodies are made quickly and the disease does not break out.

However, when Jenner made his discovery in 1790, microbes remained unknown and nothing was understood about the immune system. Observation and empiricism alone had guided Jenner in the discovery of what has since become one of the great defense weapons against epidemics.

The last case of smallpox was recorded in 1977 in Somalia. Since then, smallpox has been eradicated, wiped from the earth through systematic vaccination campaigns, to the extent that we no longer even vaccinate against it today. We are keeping a close watch for new cases. But this success is an exception. It was possible because the smallpox virus lives only in humans. There is no animal reservoir. By vaccinating humans and making them resistant, inhospitable to the development of the virus, we have deprived this virus of a way to reproduce.


Cholera, on the other hand, has not disappeared. In Basra, Iraqis are dying of it today. People are dying of it in all of the cities in poor countries where poverty and the lack of hygiene prevail.

The agent of cholera is a bacterium, Vibrio cholerae, which develops in the digestive tract and causes vomiting and diarrhea so severe that, without treatment, it leads to death by dehydration after several days. As with smallpox, humans are the microbe’s only reservoir.

No animal plays a role in the spread of cholera. It takes place directly, from person to person, after consuming water contaminated with human feces containing the bacteria. And the bacteria are very resistant, surviving for weeks in contaminated water and ground.

Cholera had long remained confined to the large, crowded, and polluted river deltas of India. It only left India at the beginning of the 19th century, when trade intensified and quickened with Europe. Six successive waves of cholera struck up until the end of the 19th century. Starting in Calcutta in 1817, the first wave extended as far east China and as far west as the Mediterranean Sea. It was during the second wave that cholera reached Europe for the first time: Russia, Poland, Germany, England, and then France in 1832. That same year, cholera crossed the Atlantic and struck New York.

When, on March 25, 1832, the first cases were detected in Paris, nobody wanted to believe it. The press ridiculed the discovery. How could France, so developed and rich, be contaminated by a disease from the Indies, those distant and miserable colonies? And yet, the epidemic was there, in full force. By the end of April, 12,800 deaths had already been counted on French territory.

The same scenes of panic and horror took place as during the plague in the Middle Ages. Poisoners were suspected, and innocent people were killed. In Paris, the number of dead bodies quickly outstripped the capacities of the city’s carpenters, undertakers, and gravediggers. Carts overflowing with corpses discharged their cargo into hastily‑dug mass graves.

At that time, in Paris in 1832, there was not enough water to do everything—seven liters on average for each Parisian. Public fountains delivered water from the Ourcq Canal, where boats and barges drifted. People also drew water from the Seine, where the city dumped its wastewater. As for the wells, they were polluted by seepage from the Seine and leaks from cesspits. The sewer system was insufficient and clogged with muck. Although certain houses in bourgeois neighborhoods had begun to have drainage systems, the working‑class neighborhoods had only the street. People just said “Look out for water!” when dumping out wastewater, and, often, the contents of chamber pots. The gutters swept along this waste from the middle of the street … into the Seine. All of the conditions needed for the spread of cholera were in place.

Mortality was much lower in rich neighborhoods than in working‑class slums, where hunger was combined with a complete absence of hygiene. This inequality in the face of death gave even more cause, if this was needed, to the anger of the working classes. In June, the riots which Victor Hugo described in Les Misérables broke out.

This epidemic outburst eventually subsided, but cholera returned. Throughout the entire 19th century, several epidemics struck, reaching every continent and causing 30 to 40 million deaths worldwide.

Cholera also claimed its share of victims from among armies at war, where overcrowding and terrible hygienic conditions favored the development of epidemics. It cut down English troops during their conquest of India. It followed French troops in Algeria, then in Vietnam. It also devastated Napoleon III’s armies during the Crimean War, at the time of the Siege of Sevastopol in 1854. Leaving from Marseille and Toulon, the cholera bacteria embarked with the troops. They may have even been brought by subjects who appeared healthy, since among certain people, the bacteria do not cause any visible symptoms. But these “healthy carriers” transport the germ and can spread it at any moment to new victims, who then form the point of departure for a new epidemic.

In 1884, the murderous bacterium, Vibrio cholerae, was isolated. The following year, the first vaccine was developed. Today, in the rich countries, cholera has disappeared. The chain of contamination has been broken, thanks to drinking water systems, flushing toilets, public health measures, and paved streets. Vaccination has also played a role, even if it is only 50% effective and lasts only for six months. In countries like France, we no longer vaccinate people, except when they are going to travel to countries where cholera still exists. And, if a case were to arise here, we have effective antibiotics and rehydration techniques at our disposal to fight the disease.

But cholera continues to kill people in Africa, the Americas, and Asia, where living conditions are comparable to those which prevailed in working‑class slums in the 19th century, or are often even worse.

The situation is the most dramatic in Africa. In 1994, a cholera epidemic took the lives of 24,000 people in the Goma refugee camp on the Congolese border with Rwanda. In 1998, 13,000 cases of cholera and almost 800 deaths were declared between January and May in the Democratic Republic of Congo. In the same period, 20,000 cases and 1,000 deaths were reported in Uganda.

“Declared” and “reported” are the key words here, since it is not known just how many cholera victims there are in this part of the world, where cholera, today a disease of the poor, remains endemic.

The Spanish Flu

Today, the flu is much less terrifying than the plague and cholera. However, in France alone, seasonal epidemics affect an average of four million people and kill 4,000 every year, primarily young children and the elderly. [In the U.S., between nine million and 45 million were infected with the flu over the last eight years, and between 12,000 to 61,000 died from it, according to the CDC.] But there have been especially deadly flu epidemics throughout history, particularly one which broke out in the spring of 1918 during World War One and which also became global: the Spanish flu. This flu was Spanish in name only. Spain was not involved in World War One, and so, when the epidemic broke out, Spain was the first country to acknowledge it. The countries at war, for their part, preferred to say nothing about it, in order not to reveal to their enemies how much their troops had been weakened.

The pandemic developed in three successive waves: in the spring of 1918, in the autumn of the same year, and then in the spring of 1919, the last two of these being the deadliest. The transport of troops back and forth across the Atlantic played a role in the intercontinental spread of the epidemic. During its second wave, among the U.S. soldiers ready to embark from Boston, 13,000 were infected.

But for all that, it was no question of delaying their departure for France, on the orders of President Wilson. By the time they arrived, six per cent of the sailors had died.

During the two years that the epidemic lasted, soldiers were not its only victims; it soon reached the whole population. The Spanish flu caused 20 million deaths, twice as many as the World War itself. It sowed terror everywhere, and, throughout the entire interwar period, this terror returned every flu season, out of fear that it would be as deadly as the Spanish flu.

The flu virus was not isolated until 1933, when it was discovered to be an Orthomyxovirus. Like all viruses, it has to hijack a cell in order to reproduce. In this case, it targets the cells that line the inside of the nose, throat, and bronchial tubes. It is therefore especially contagious. All it takes is a fit of coughing, a sneeze, or a simple breath for a multitude of viruses to spread through the air and penetrate the nose, the throat, or the lungs … of bystanders. The virus is also particularly formidable because we are not immunized, or are only partially immunized, against it.

When, as a child, someone “catches” measles and recovers from it, they can no longer “catch” it. The antibodies which the organism produces during the first infection are memorized, and, whenever it comes into contact with the same virus again, it immediately produces large quantities of these antibodies. This is why we do not come down with measles twice.

With the flu virus, nothing of the sort happens. This is because there are many strains of viruses which differ among themselves, especially in terms of the structures that allow them to attach to the cells which they infect. This variation comes from the frequent changes—or mutations—to their genetic material. Flu viruses are therefore never exactly the same.

Most often, these changes are small, but they are nevertheless enough to make it so that antibodies produced in 2003 are no longer entirely effective in 2004, creating a low‑mortality epidemic. On the other hand, these changes are sometimes so important that previously‑made antibodies have no effect against the new virus. This is what happened with the Spanish flu. In each of the epidemic’s three waves, the virus was “new.” The antibodies made in the previous wave were ineffective against the virus in the next one.

Fortunately, these major changes only happen occasionally, such as when pigs are simultaneously infected by a bird flu virus and a human flu virus. This is rare, because the different viruses are generally specific to a given species. But when this does happen, the two types of virus reproduce in the pig’s lung cells. When they leave the lungs, some of them are “hybrid” viruses, sort of half‑bird and half‑human. For humans, they are totally new….

Another epidemic is useful in order to better understand the unpredictability of the flu virus: the Hong Kong flu which broke out in 1997. Within several months in 1997, 18 deaths from flu were observed. It was not so much the number of deaths which caused people to worry, but more the fact that bird viruses were isolated in the victims. Until then, it was thought that bird flu viruses could not infect humans. This caused a panic. Out of fear of a major pandemic, 1.2 million chickens were slaughtered. The human epidemic stopped. The main reason for this was that, although chicken viruses could pass to humans, the disease could not then spread from person to person.

The flu virus’s capacity for rapid mutation is the reason for the potential seriousness of any new epidemic. This led to the establishment of a common monitoring system at the national and international levels.

At the international level, the World Health Organization (WHO) is made up of 110 national centers in 80 countries, which constantly transmit their data to four global collaborating centers (Atlanta, London, Melbourne, and Tokyo). It is on the basis of this information that the types of virus recommended for the production of the flu vaccine are determined every year at the end of February, so that they can be in pharmacies in November.

The flu virus is tracked and closely followed. The fear of a pandemic like the Spanish flu returning, with its suddenness, rapid spread, and mortality, is justification enough not to put our guard down at a global level.

Ebola and AIDS

Ebola, AIDS, SARS … we often see these names in the headlines [and today COVID-19]. Essentially, these terrible diseases have been caused by infectious agents, which are new or unknown until recently and against which we have often been powerless.

The Ebola virus is named after a river in Zaire (today the Democratic Republic of the Congo), where its first epidemic was discovered in 1976. Since then, it has regularly reappeared, each time in the same tropical regions of sub‑Saharan Africa. [The last epidemic struck in 2016-2018 in West Africa; 28,000 people were infected, 11,000 died.]

Ebola is so worrisome, not because it spread across the globe like the flu or smallpox viruses, but because it is a formidable killer which leaves no hope for its victims. Death comes in 6 to 10 days. After a sudden outbreak of fever, the body hemorrhages blood from the mouth and eyes. The skin softens to the point at which it falls apart upon touch, and the liver breaks down.

Our knowledge about the virus is still very limited. It was isolated and imaged using electron microscopy. But we do not know how it reached us nor what animal is its reservoir.

Scientists have searched for the virus in 18,000 animals and 30,000 insects in the Congolese jungle, but with no results for the time being. Hunters became contaminated after eating monkey. However, the monkeys are not the reservoir for Ebola, since they are themselves victims of the virus. This is one of the factors which causes us to fear that African great apes might disappear in the next 30 years.

Although we do not yet know how Ebola infects us, we do know that it is transmitted by simple contact between people. It can be found in all of the excretions of people with the disease, but fortunately it cannot be transmitted through the air. It is therefore the families and caregivers, who are in direct and repeated contact with Ebola victims, who are most often infected.

To prevent the spread of the epidemic, health authorities have imposed a strict but effective quarantine. People are forbidden from entering infected villages and forbidden from visiting sick patients in the hospital. This is not easily done, since families in Africa take on much of the burden of caring for the sick. They also needed to be convinced to stop ritual practices of cleansing the dead by purging the diseased person of their excretions in order to prepare for the funeral. But the population has complied with these measures, which prevented a spread which would have been—and would be—catastrophic for the big African cities and for other continents.

In 1976, at the moment when Ebola began its tragic career, another serial killer had already entered the fray: the AIDS virus, which appeared for the first time in humans at the beginning of the 1970s in the same part of Africa. Ten years later, one of the most terrible pandemics ever to strike humanity began in the United States. To this day, AIDS has killed as many people as the plague or the Spanish flu: 40 million people have been infected, and more than half of them have died. The pandemic continues to spread, since it is estimated that 6,000 new people are infected every day. It cruelly strikes the poor countries where 95% of AIDS victims can be found today, mostly in Africa, but in Asia as well.

Comparisons with the plague do not stop there since, in the 1980s, one might have believed oneself to have stepped back centuries ago. At the start of the epidemic, the relatively high infection rate of homosexuals and drug addicts left the door open to the worst reactionary ideas. Some claimed that those who had the disease, and even those who were HIV‑positive (meaning that they were carriers for the virus but had not yet developed the disease), were contagious.

Some campaigned to isolate and confine them. Others refused to hire them or to rent them an apartment. In Switzerland, it was even proposed to tattoo them. And all sorts of priests were not to be outdone, refusing to marry people with AIDS or to bury them.

However, scientists have gained considerable knowledge about the virus since 1981. We know that it infects and eventually destroys some of our white blood cells, which paralyzes our immune system. It has even been discovered that this “emergent” virus is the human version of a monkey virus, SIV, which mutated and adapted to humans. Healthcare professionals have become increasingly able to deal with AIDS, inventing more and more effective treatments. Today, thanks to triple combination therapy, which combines three antiviral medications, we know how to limit the multiplication of the virus and therefore to extend the lives of AIDS patients. AIDS has become a disease like the others, or at least one that does not have 100% mortality.

Some people have lived with the virus for more than 20 years. And many researchers and resources have been devoted to the development of a vaccine.

However, triple combination therapy is only available for patients in rich countries and for rich patients in poor countries. This is because the medications are commodities like the others: they are produced in order to be sold. The pharmaceutical industry is dominated by monopoly corporations, which are among the wealthiest in the world, setting their sights only on profits. It ought to be remembered that these corporations dared to file a lawsuit against the South African government in 1998 for having violated their sacrosanct patents by authorizing the local manufacture of anti‑AIDS drugs.

Facing the anger this raised, the defenders of profit at any cost, partisans of a true healthcare apartheid, finally retreated a little in 1999. But they proved, once again, that the borders of poverty remain high in terms of access to healthcare.


SARS stands for severe acute respiratory syndrome. These four letters denote a new disease which has set off a wave of panic across the planet.

In Beijing, people rushed to board trains and flee the disease, their faces covered by masks. Schools were shut down. In Singapore, in airports turned into transit camps, authorities used thermal scanners to search for people with fevers above 100℉. They were then placed under quarantine, surveilled at home using cameras and electronic monitoring bracelets. The Centers for Disease Control issued a travel advisory for Canada. And in the countries which were not, or barely, affected, like in Europe, some people already felt themselves besieged by this new microbe, so modern that it used intercontinental jets.

Since March 2003, the date when the WHO issued a global alert for the first time in its history, the atypical pneumonia SARS has crossed borders and oceans to reach every continent, infecting almost 8,000 people and killing nearly 700 people in 31 countries.

The disease begins with a respiratory infection characterized by a fever of more than 100℉, coughing, and difficulty breathing. In almost 10% of all cases, it progresses to a respiratory breakdown against which we have no effective treatment.

Faced with this epidemic, of which we had no idea how far it would spread, we have never reacted so quickly in the history of medicine. And thanks to the Internet, information and discoveries have circulated even quicker than the epidemic between the 11 laboratories worldwide which the WHO has tasked with discovering the cause of this disease. In less than one month, scientists have shown that SARS is caused by a virus from the coronavirus family, so called because, under an electron microscope, they appear to be surrounded by a crown.

This family of virus has already been observed in humans. But because coronaviruses seemed to cause only benign colds, doctors had not devoted much time to studying them. Veterinarians are more familiar with them, since they are much more aggressive in pigs, cows, and poultry.

The coronavirus discovered in March 2003 is a new virus. Like the flu virus, it was reportedly the result of a recombination of human and animal coronaviruses within pigs, which gave rise to this mutant virus, much more aggressive. As with the flu virus, the closeness of barnyard poultry, pigs, and humans likely facilitated the emergence of this new coronavirus. And the epidemic broke out in a province of southwest China, probably because this is a region where pig farming is intensive and closely concentrated. But scientists are far from having confirmed all of this. Biologists have just discovered a coronavirus very closely related to the SARS virus in small mammals called civets, the meat of which is highly valued in Hong Kong. Is it the same virus? Is the civet the “vector” of the coronavirus which causes SARS? Only the future will tell.

Although the epidemic was declared in 2003, it actually broke out four months earlier, in November 2002. In the meantime, almost 800 Chinese people were infected, and about 30 died. It was probably a Chinese doctor who was still in the incubation period when he traveled to Hong Kong, transmitting the virus to tourists, businesspeople, and others, who themselves brought it to Toronto, Singapore, and Hanoi. The Chinese government only recognized the epidemic’s existence in February 2003 when the first SARS cases appeared among the ruling elite, causing them to panic and establish measures to quarantine ministers and senior officials in their guarded residential neighborhoods.

The SARS coronavirus spreads easily through the air. Sneezing and coughing give it wings. It is not a killer virus like Ebola or the AIDS virus. Its mortality rate is closer to that of the flu. But unlike the seasonal flu, it can kill young adults. Neither is it a very resistant virus: it can survive only a few hours outside of the human body. Finally, if we might think it to be an especially aggressive virus when we observe its rapid spread across the planet, we must also remember that the AIDS virus, which took more than 10 years to leave its native Africa, has caused much more damage since then.

And so, where does this leave us? The drastic quarantine measures taken by Hong Kong and Vietnam, which closed their borders with China, seem to have worked, and the WHO has announced that the spread of the virus on a worldwide scale has generally been checked. But it continues to develop in China and Taiwan. Some are already describing atypical pneumonia as the flu of the 21st century. Is it a controlled epidemic or a pandemic? We do not yet know. We must wait to find out.

In any case, our medical understanding is infinitely greater for diseases like SARS, Ebola, and AIDS, when compared with what was known at the time about the plague in the Middle Ages, cholera in the 1830s, and even the flu at the beginning of the 20th century. And as the SARS epidemic has shown, this knowledge is growing faster and faster.

We have already said that it would be an illusion to imagine a world without microbes. They have accompanied us for millennia, adapting and transforming themselves. On the other hand, we have medications at our disposal—vaccines, antiviral drugs, and antibiotics—which are increasingly effective and have fewer negative side effects. And we will discover others. But we will only defeat the harmful effects of epidemics when the entire population of the world will finally have access, materially and culturally, to all of these possessions and knowledge of humanity.

May 2003 [Inserts May 2020]